Benchmark: find() vs for...of vs for-loop large array fixed

HTML Preparation code:

<div id='test'></div>

Script Preparation code:

window.arr = Array.from({ length: 1000 }, (_, i) => i)

Tests:

for-loop
let val; for(i=0; i<arr.length; i++){ var value = arr[i]; if (value === 900) { val = value; break; } }
for..of
let val; for (var value of arr) { if (value === 900) { val = value; break; } }
Array.find()
let val = arr.find(node => node === 900);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for-loop
for..of
Array.find()

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark that compares three different approaches for finding an element in a large array:

1. **Native Loop**: A traditional `for` loop using the `length` property to iterate over the array.
2. **`for...of` Loop**: An iteration method introduced in ECMAScript 2015, which uses the `for...of` statement to loop over iterable objects, such as arrays.
3. **`Array.find()` Method**: A built-in method on the `Array` prototype that searches for an element in the array.

**Test Case Explanation**

The individual test cases are defined within a nested JSON structure. Each test case has:

* **Benchmark Definition**: The code snippet that represents the benchmark being tested.
* **Test Name**: A brief description of the benchmark.
* **Script Preparation Code** and **Html Preparation Code**: Optional code snippets used to set up the environment for each test.

The three test cases are:

1. `for-loop`: A traditional `for` loop using the `length` property to iterate over the array.
2. `for..of`: An iteration method introduced in ECMAScript 2015, which uses the `for...of` statement to loop over iterable objects, such as arrays.
3. `Array.find()`: The built-in `Array.find()` method that searches for an element in the array.

**Pros and Cons of Each Approach**

Here's a brief analysis of each approach:

1. **Native Loop (`for-loop`)**:
	* Pros: Typically faster due to low-level memory management and iteration control.
	* Cons: Requires manual indexing and bounds checking, which can be error-prone.
2. **`for...of` Loop**:
	* Pros: Easier to read and maintain than traditional `for` loops, with reduced risk of off-by-one errors.
	* Cons: May be slower due to the overhead of creating an iteration context.
3. **`Array.find()` Method**:
	* Pros: Concise and expressive code, with built-in support for searching large arrays.
	* Cons: May not perform as well on very large arrays or memory-constrained environments.

**Library Used (if any)**

None of the provided benchmark definitions rely on a specific library. The `Array.from()` method is used to create a large array in the script preparation code, but this is a built-in JavaScript function.

**Special JS Feature/Syntax**

The only special feature used in these benchmarks is the introduction of the `for...of` iteration method in ECMAScript 2015. This syntax allows for more expressive and concise code when iterating over iterable objects like arrays.

**Other Alternatives**

Alternative approaches for finding an element in a large array might include:

* Using `Array.prototype.indexOf()` or `Array.prototype.lastIndexOf()`, which return the index of the first/last occurrence, respectively.
* Employing custom linear search algorithms, such as binary search, to improve performance on very large arrays.

Keep in mind that these alternatives may have different trade-offs in terms of code readability, performance, and memory usage.

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:123.0) Gecko/20100101 Firefox/123.0

Browser/OS: Firefox 123 on Linux

View result in a separate tab

Test name	Executions per second
for-loop	60038.1 Ops/sec
for..of	175157.3 Ops/sec
Array.find()	374247.3 Ops/sec

Related benchmarks:

find() vs for...of vs for-loop large array fixed (version: 0)

Testing the difference between native loops and find()

Comparing performance of: for-loop vs for..of vs Array.find()

Created: one year ago by: Guest

Jump to the latest result

for-loop

for..of

Array.find()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):